Dual boot system with UEFI and Fedora 20 and Windows 8.1

In short sentences:

Yes it is possible! Even with secure boot enabled!

The long version:

On my workstation I use a dual boot configuration for some games and my
Linux based development and testing. Since I am using a UEFI only
configuration it was quite easy to use a dualboot configuration with
Fedora 20 and Windows 8.1.

I turned off the legacy mode on my board and reactived the secure boot
option I disabled some time ago for testing. The most UEFI boards should
come with this options as their default values. Since I connected each
system HardDisk/SSD seperated for installation, Fedora couldn't
recognize the Windows disk and the boot menu entries automatically. This
was just to protect my data since I am using two equal SSDs with the
same size I didn't want to risk to select the wrong and loose all my
data.

The Fedora disk is my first boot disk and I only added these lines to
the grub.cfg located on the EFI partition
(/boot/efi/EFI/fedora/grub.cfg) to add the Windows entry: